• Journal of Microbiology and Biotechnology
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• 제31권4호
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• pp.520-528
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• 2021

Plesiomonas shigelloides, a member of the family Vibrionaceae, is a gram-negative, rod-shaped, facultative anaerobic bacterium with flagella. P. shigelloides has been isolated from such sources as freshwater, surface water, and many wild and domestic animals. P. shigelloides contains 102 O-antigens and 51 H-antigens. The diversity of O-antigen gene clusters is relatively poorly understood. In addition to O1 and O17 reported by other laboratories, and the 12 O serogroups (O2, O10, O12, O23, O25, O26, O32, O33, O34, O66, O75, and O76) reported previously by us, in the present study, nine new P. shigelloides serogroups (O8, O17, O18, O37, O38, O39, O44, O45, and O61) were sequenced and annotated. The genes for the O-antigens of these nine groups are clustered together in the chromosome between rep and aqpZ. Only O38 possesses the wzm and wzt genes for the synthesis and translocation of O-antigens via the ATP-binding cassette (ABC) transporter pathway; the other eight use the Wzx/Wzy pathway. Phylogenetic analysis using wzx and wzy showed that both genes are diversified. Among the nine new P. shigelloides serogroups, eight use wzx/wzy genes as targets. In addition, we developed an O-antigen-specific PCR assay to detect these nine distinct serogroups with no cross reactions among them.

• IMMUNE NETWORK
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• 제13권5호
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• pp.184-193
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• 2013

Co-signaling molecules are surface glycoproteins that positively or negatively regulate the T cell response to antigen. Co-signaling ligands and receptors crosstalk between the surfaces of antigen-presenting cells (APCs) and T cells, and modulate the ultimate magnitude and quality of T cell receptor (TCR) signaling. In the past 10 years, the field of co-signaling research has been advanced by the understanding of underlying mechanisms of the immune modulation led by newly identified co-signaling molecules and the successful preclinical and clinical trials targeting co-inhibitory molecules called immune checkpoints in the treatment of autoimmune diseases and cancers. In this review, we briefly describe the characteristics of well-known B7 co-signaling family members regarding the expression, functions and therapeutic implications and to introduce newly identified B7 members such as B7-H5, B7-H6, and B7-H7.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.136-145
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• 2010

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called $V{\alpha}14J{\alpha}18$ in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, ${\alpha}-galactosylceremide$ (${\alpha}-GalCer$), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and $interferon-{\gamma}$. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with ${\alpha}-GalCer$. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.

• IMMUNE NETWORK
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• 제16권2호
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• pp.134-139
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• 2016

Programmed death-1 (PD-1) is a strong negative regulator of T lymphocytes in tumor-microenvironment. By engaging PD-1 ligand (PD-L1) on tumor cells, PD-1 on T cell surface inhibits anti-tumor reactivity of tumor-infiltrating T cells. Systemic blockade of PD-1 function using blocking antibodies has shown significant therapeutic efficacy in clinical trials. However, approximately 10 to 15% of treated patients exhibited serious autoimmune responses due to the activation of self-reactive lymphocytes. To achieve selective activation of tumor-specific T cells, we generated T cells expressing a dominant-negative deletion mutant of PD-1 (PD-1 decoy) via retroviral transduction. PD-1 decoy increased IFN-γ secretion of antigen-specific T cells in response to tumor cells expressing the cognate antigen. Adoptive transfer of PD-1 decoy-expressing T cells into tumor-bearing mice potentiated T cell-mediated tumor regression. Thus, T cell-specific blockade of PD-1 could be a useful strategy for enhancing both efficacy and safety of anti-tumor T cell therapy.

• 한국동물학회지
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• 제34권4호
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• pp.469-478
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• 1991

The CALLA on the surface of leukemic cell lines, recognized by our monoclonal antibody. KP-22(IgG1, K) was one of cell surface glycoproteins having moi. wt. of approximately 100,000 dalton, and could be shed in spent medium or endocytosed when binding the cognate antidoby, KP-22. In the presence of cognate antibodies, 60% of CALLAS recogniEed by KP-22 MAs were modulated and cleared from the cell surface during 24 hrs, and approximaetely 35% of them was endocytosed and 25%, was shed in spent medium. The reappearance of the membrane CALLA after modulation by the KP-22 required at least 6 hours and supposed to be newly synthesized molecules.

• BMB Reports
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• 제38권6호
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• pp.683-689
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• 2005

Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying ahexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5% of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100% with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.

• 미생물학회지
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• 제51권2호
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• pp.115-125
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• 2015

단일클론항체 AP64 IgM은 인간의 급성 비임파성 골수암(ANLL) 세포주 HL60에 결합하며 쥐의 ANLL 세포에도 교차결합(cross-react)한다. 또한 complement에 의해 매개되어지면 골수암 억제효과를 나타낸다. 본 연구에서는 RT-PCR에 의해 AP64 IgM을 분비하는 하이브리도마의 $V_H$ 및 $V_L$ cDNA로부터 유래된 재조합 single-chain variable domain fragment (ScFv)를 제조하였다. $V_H$ 및 $V_L$은 15개 아미노산으로 구성된 linker $(G_4S)_3$으로 연결되었다. 재조합 ScFv는 Escherichia coli BMH 71-18에서 single polypeptide chain으로 발현되었다. Periplasmic extract를 $Ni^+$-NTA-agarose affinity column에 가하여 발현된 재조합 ScFv를 정제하였으며 westernblot으로 정제된 단백질을 탐지하였다. 정제된 재조합 ScFv는 AP64 IgM 모항체가 탐지하는 항원과 같은 HL60 세포의 표면항원(약 30 kDa)을 인지하였다. 그러나 HL60의 표면항원에 대한 ScFv의 결합력은 AP64 IgM 모항체보다 낮아서 추후 이에 대한 개선이 필요하다. 종합하여 볼 때 HL60 세포주에 특이적인 재조합 ScFv는 진단 또는 치료목적으로 유용한 생물학적 제재가 될 수 있을 것이다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.468-472
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• 2003

Recently, genetic engineering techniques have been used to display various heterologous peptides and proteins (enzyme, antibody, antigen, receptor and fluorescence protein, etc.) on the yeast cell surface. Living cells displaying various enzymes on their surface could be used repeatedly as 'whole cell biocatalysts' like immobilized enzymes. We constructed a yeast based whole cell biocatalyst displaying T. reesei cellobiohydrolase I (CBH I ) on the cell surface and endowed the yeast-cells with the ability to degrade cellulose. By using a cell surface engineering system based on ${\alpha}-agglutinin,$ CBH I was displayed on the cell surface as a fusion protein containing the N-terminal leader peptide encoding a Gly-Ser linker and the $Xpress^{TM}$ epitope. Localization of the fusion protein on the cell surface was confirmed by confocal microscopy. In this study, we report on the genetic immobilization of T. reesei CBH I on the S. cerevisiae and hydrolytic activity of cell surface displayed CBH I.

• 한국동물위생학회지
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• 제30권2호
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• pp.205-209
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• 2007

A protein chip based on surface plasmon resonance (SPR) imaging was developed for measuring classical swine fever virus (CSFV) antibody using a recombinant gp55 protein as an antigen. The diagnostic potential of SPR imaging for detecting antibodies to the CSFV gp55 protein was compared with that of a enzyme -linked immunosorbent assay (ELISA) using 70 pig sera. There was a strong positive correlation between the SPR imaging and ELISA (n=70, r=0.916, p<0.01). Therefore, the SPR imaging, which is a label-free and high-through put method, is expected to be a valuable tool in the serodiagnosis of CSFV.

• Rapid Communication in Photoscience
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• 제2권2호
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• pp.46-51
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• 2013

This study reports a fiber-optic sensor detecting biomolecule by simultaneously monitoring localized surface plasmon resonance (LSPR) from gold nanoparticles (Au NPs) of ca. $50{\pm}5$ nm attached on one end of optical fiber and surface enhanced Raman scattering (SERS) of the reporter molecules adsorbed on the gold surfaces as an additional sensing tool. The sensor was fabricated by immobilizing Au NPs on one end of an optical fiber by chemical reaction. LSPR and SERS signals of the sensor were measured using various refractive indices solutions. Finally, the sensor was applied to observe real-time LSPR sensor-gram and SERS spectra of the reporter molecule of 4-aminothiphenol during the antibody-antigen reaction of interferon-gamma (IFN-${\gamma}$) as a proof-concept experiment of biological applications.